Core for metal casting molds



June so, 1931, c. L. LEE Em. 1,812,491

CORE FOR METAL CASTING HOLDS June 30, 1931. c. LEE ET AL 1,812,491

CORE FOR METAL CASTING MOLDS Filed Nov. l2, 1928 2 Sheets-Sheet 2 Snom/rtw Elftor m13' Patented June 30, 1931 UNITED STATES PATENT OFFICE CHARLES Il. LEE, OF DAYTON, OHIO, AND THOMAS C. VAN DEGRIFT, OF DETROIT, lVIICI-IIGrAkN, ASSIG-NORS TO GENERAL MOTORS RESEARCH CORPORATION, OF f DETROIT, MICHIGAN, A CORPORATION F DELA\VARE CORE FOR METAL CASTING IVIOLDS Original application led April 22, 1925, Serial No. 24,968. Divided and this application led November 12,

This application is a division of applicaytion Serial No. 24,968, filed April 22, 1925, for thecasting of metals in permanent molds.

The invention claimed in this application relates to cores and consists of a body of sand or like core material molded to a permanent base which forms a part of the complete core and facilitates centering in thekmold.

y In the drawings in which like parts are 1b indicated by like reference characters throughout the several views: n

- Fig. l is a fragmentary View partly in side elevation and partlyin section of a molding apparatus showing one-half of the core in vertical sect-ion.

Fig. 2 is a fragmentary view partly in side elevation and partly in section showing the mold carriers retracted, the mold open and a core resting on the core platform.

Fig. 3 is an elevation disclosing the inner side of one section of a piston core box.

` Fig. 4 is'an elevation of a complete piston core box.-

Fig. '5 is a bottom plan view of a piston core box with a metallic core centering member in place.

, Fig. 6 is section on line 66 of Fig. 5.

In the illustrated'embodiment of the invention, A indicates the base of a casting apparatus to which are attached the molds, mold carriers, Operating mechanism therefor, and a yielding core platform. B indicates .carriers to which mold sections C may be detachably secured. When the mold sections C are closed in position to receive molten metal,

they are disposed substantially ycentrally above the base and above .a platform indicated by the letter E, whichV is preferably mounted on springsso as tov yield downward. 40 The platform E may have a surface adapted to contactwith the metal of the casting and form of itself, a section of a mold, or it may support on its surface 4a part of a mold, and Y the yielding of this part owing to the eX- pansion of thecasting avoids the necessity of providingmeans to let the mold sections C yield Y laterally under such conditions. In Figs. lland 2, a core D is shown in place on the platform E, ,said core having a flangelike vbase which closes the 1tower open'ends Serial N0. 318,708.

of the sections C, shown in the drawings as sections of a piston mold, although obviously the sections may be formed as a reverse of other objects than pistons.

As this application relates to the core the detail description following ywill be limited to the core and so much 'of the apparatus as may be helpful in affording an apprehension of the utility of the core construction.

The kcore body may be made of green sand or baked oil sand or of other suitable ma. terial customarily used for cores. The body 65 of core D is of course a patria the reverse in contour of the interiorr of t-he piston or other body to be cast. The. body 6G is combined with a fiange-like base 67, which, in

the example shown, is circular and has' its upper surface 68 parallel with its under surface 69, both of said surfaces being perpen dicular to the axis of the core; whereby with a supporting surface or surfaces 53 on platform E trued in a plane perpendicular to the axis of the core and mold sections, the core may be readily centered with respect to said mold sections so that the casting produced will be accurate, and, in the casting of a piston for example, the walls will be of even thickness circumferentially.

The corev base 67 is preferably formed of metal combined with sand or other core ma terial molded together. .The metallicpor-4 tion of the core base 67 may consist of a me-V tallic centering member 7 (l having a. rim or annular exterior 71 connected to a-central perforated hub 72 by radiating spoke-like members 73 (Figs. l, 5 and 6). Theopen spaces between rim, hub and spokes are filled with sand or other core material during the process of forming the core. The metallic centering member should have the lower and upper surfaces of hub and rim machined vor otherwise trued in parallel planes perpendic ular to the axis and to the cylindrical perim-' eter. The spokes may be of lless height than said hub and rim so as not to cont-act with the core base. Said .centering member may be joinedwith the core material in a mannerto be now explained.

'Referring to Figs. 3, 4, 5 and 6, F represents a core bex as a whole.- The core box F at the upper portionl of said section. The said ears 81 and 83 of each pairhave-perfora.- tiene Whioh. register when theeeobore rrerboh.. Pins 84 and 85 maintain correct registration. The locking members 78, When turned to lock: ieg. moitier, ergere .the lege 8.0, Seid luge 80 enteren fh e e openings@ .ie the looking merole. .re Lueeereeoformed that .warming engagement between 9118.111 and the locking .olreire the .bw-o Seetioneelose together er1.' @Lemire there .rigidly- The bese portion 32 .SPlIa-fer'by .lQCllaSely bored .or otherywieefrireolrirled. to reoere the eore-Ceeeeriog member 7,0, `Kand has ,the surface 86. perpendicf. 111er to. the .erle .of .the Core borv So .that Seid member-YQ ies...r1.e.ee1.y Within .Seid heee with .ite errer erlol loire? eerfeeee also perpen- .Clioule .tet-he @Xie of the Gore-bor! When the bor .ie .to loe fllled with eore materiele tlleiooreeor Should be inverted from if-11e Position-in'.irholliijie shown in .Fge 14 aridi. nel, Wide-...the oerlterine member in Pleoe ieiroirld Peer aeoFg- 5, ifloolred etgiroie .elo .The-@Ore iborfmefy be .filled with eer-embed@ wh-oh may be eamioed therein until it reaches a'level a little below.r tlieeer-feoe6.. Then the centering member @may be .eeereft iola-re-beingtekerl tor have ille-e1l11rfeoel86. .perfectly free fromeerd .or other pertele and @remember 7.0 .likewise eeeeleen Sol thee-the bese Serfeoewoff-he oenterirg .rire .will be eooeretely positioned with respectto thea-Xis of the core box. Sandor. othereore materiel mei there loe tempedprito. the.. .core-.bor .through .the oreil- .ieg'e between the rim, Spokes eed heb of .the I Iieilloer @mail seid materiel ie peoked. .Solid-y oi .Said oenteregriremher. f

.'.Rerertl s' rovetothez mold. .Carriere B- .eed roeiers. ,for operating;ther1=-he-eerriere .B erePiYoi-erl totheioerrer lerere.. lo order that .theoerriersl 111er loe eeueed. to open wide tor- .,reedy eeeeeetotheloore ypleibfor-rl erdftlt mold. eotoile' reedilyeeees'siloleor ectgg joiotherwise. eoetrng;membereshermg oerewefys ereooreeoted .to-the heee A. which .ooor-...eretee with logeori 'theearriere B., seid .Luge and' oereweye. heilig-feo. dieo'oeed. as micorurel the otlier'ear 83 diagonally oppositethe .ear 81,..

to.. suoli engleeereo mekeiheieeoleeof the of each cam member 87 is an inclined lcam groove 90, lyingbetvveen a lower guide Wall 91 and a. shorter upper guide Wall 92. A lug 9.3 oneach `carrier B supports aside pin preferably having a roller -94 guided inthe groove 90. Vhenthe mold carriers are Wide open, as shown in Fig. 2, the carriers may be tilted Ibach still further aboutthe. .pivots 26,' as the cause a parallel movementof ythe mold fac-es in the Viinal closing and initial openingfstages. For convenience yof mil-Illlfefllre, the earn members for each mold 4carrier ,are identical and are consequently reversed imposition With respect to each other when mounted er1-the e-ioperetue.

.Referring 'to the Construction of the.. .mold Seot'one ...Cr Eeoh moldA Seetoefhas .eloiver end constituting a ledge 95 which is preferably machined plane in the .case of the piston mold shown, elle perpendicular to the'. .arie .of said sections. Outside of and depending ybeloW the ledge ,95 are centering lugs96 Aand 97, Each lug 96 is disposed on almold sectiondirectly over a surface :54.011 base E While the luge 97 ere 'Deer theedges of the .seetiorr YIrl a piston or'lilre mold'the inner :faces of the lugs I are substantially coincident With a ,circle of thesaine diameter Ias the centering 11161D- ber 70 of the core. The lugs are intendedto engage .the outside of rim 71 of centering member 70, when thel molds are moving to closed position and center thencore with' re- Speot to .the mold eeetone.- 'The ledge 9.5

that the core is clamped to the top surface 53 of the base snugly and accurat'elyL. By

means the Vcore is sure to be 'centered' accu-A rately sothat .the vWalls of tliepiston cast ,in the ledges `9.5 Willalso clamp down on the upper surface 68 of thecore base 6,7 constitutes with the core a p art..,o i the complete inold closing the loiverend .ofinold cavity 43. When metal Y poured into, the mold through gatev ,44-eX-pands .on Cooling, pressure von .the surface `GS and onthecore maycause theco're platform to yield :suiiiciently lto take care of expansion. In Preperrre. for pouring e .Gestire the mold sections are causedto occupy the position shown Vin Fig. 2. In this position the molding surface of the. molds may be seated or otherwise Coated .readily-v Wth molds .in thepoetorl, ready. eooeee oen bebed to the eofre platform- A core. roede es. desribed in.

the core box F may be set on the surface 53 of the core platform E. No particular care to set the core accurately need be taken other than to see that no particles of sand lie between the surfaces 53 on the core platform and the bottom of the core base, and that the surface 68 is clean. Grooves 58 and 59 in the platform E facilitate removal of particles from the surfaces 53. The core may, of

course, be coated at this time or previously if desired. The mold may then be closed as shown in Fig. l. As the mold sections approach final closed position, the centering lugs will Contact with the perimeter of the ring 71 of core-centering member 70, if the core is not in central position, and the core will thereby be moved to final position. The ledges 95 will also clamp down on the upper surface of ring 7l and hold the core firm and true with the surface 68 forming the bottom of the mold. The mold is now ready to receive molten metal which may be poured into gate 44. WVhen the casting has set, the mold sections are moved again to the open position illustrated in Fig. 2.

While the embodiment disclosed herein constitutes a preferred embodiment, it is understood that other might be adopted within the scope of the ensuing claims.

What is claimed is as follows:

l. In a casting apparatus, a non-metallic core body having a flange-like base combined with a metallic body having a rim and spokelike members, the space between the spokelike members being filled with core body material.

2. In a casting apparatus, a non-metallic core body having a iange-like base combined with a metallic body having a rim, a perforated hub-like center and spoke-like members radiating from the hub-like center to the rlm.

3. In a casting apparatus, a core consisting of a non-metallic body united to a metallic base the latter having a perimeter extending parallel with the core axis and a plane supporting surface flush with one end of the core and perpendicular to the core axis and the perimeter.

4. In a casting apparatus, a core consisting of a non-metallic body united to a metallic base at one end, said base having a plain cylindrical perimeter parallel to the core axis and parallel plane surfaces perpendicular to the core axis and perimeter and of greater diameter than the core body.

In testimony whereof We aiix our signatures.

CHARLES L. LEE. ao THOMAS C. lVAN DEGRIFT. 

